Clue in the postage stamp?
While the year may have been missed off Tom Diggory's postcard during the franking process, I wondered if I could glean anything useful from the stamp itself which might help establish a date.
I posted a close-up photo on Twitter and it was suggested the card was posted somewhere between 1904 and 1910. That would tie in with the half-penny stamp's image of Edward VII who died in 1910.
The card wouldn't have been sent as early as 1904, as Tom would only have been 11 years old. But by 1911 he was already working at Wergs Hall, as I'm aware from the census. However I don't know how long before then Tom joined the staff.
Someone on Twitter pointed out that as postage stamps remain valid for some time after they're issued, the stamp could easily have been used after 1910.
So, while I haven't made much progress in establishing a more exact date, at least I've confirmed that my best-guess at around 1911, is probably a sound one.